Like a tsunami, a great social and cultural wave is moving west to east in this country, favoring the decriminalization and legalization of marijuana.

Naturally, it started in California, which officially allows medical marijuana and unofficially permits private use without making a fuss about it. People grow pot in their backyards, next to the zucchini and tomato plants. It’s all cool. But that’s California, home to surfers and aging hippies.

Who would expect pot to pass in the Colorado legislature? As we all know, Colorado made marijuana legal as of the new year, and stores opened throughout the state, raking in some $5 million in taxed and regulated sales in just one week. Mind you, this is marijuana sold to anyone over 21, for recreational use. In Boulder or Denver or Colorado Springs, you can enjoy a joint or a pipe or a vaporizer of pot in the way some folks sip a martini or enjoy a beer.

Washington State has also legalized recreational marijuana and — very important — the Justice Department has put its imprimatur on these first legal-pot laws, allowing them to go into effect. This sends a signal to other states that the tsunami is coming their way.

As a teenager in the Sixties, I knew about pot, but I didn’t smoke. Quite conservative and (in retrospect) awfully uptight, I was pretty much a teetotaler. I could have been very comfortable as one of those grim ladies preaching the evils of alcohol in the years before Prohibition.

Like the “reefer madness” hysteria, the temperance movement had popularized the belief that alcohol was the major cause of most social problems, and Prohibition was seen as the solution to the nation’s poverty, crime, violence and other ills. When Prohibition was ratified in 1920, the evangelist Billy Sunday said, “The slums will soon be only a memory. We will turn our prisons into factories and our jails into storehouses and corncribs.” Since alcohol was to be banned, and since it was seen as the cause of most, if not all, crime, some communities actually sold their jails.